Manifest File

Explanation

A manifest file is a structured text document that a streaming player fetches at the start of playback to understand the structure of the video stream. It lists the available quality levels (bitrate ladder), the URLs of each video segment, segment duration, subtitle and audio tracks, and DRM information. For HLS streams, the manifest is an .m3u8 file. For MPEG-DASH streams, it is an .mpd (Media Presentation Description) file. When you press play on Netflix, the app first fetches a manifest file, then begins downloading the video segments it describes. The manifest also enables adaptive bitrate switching — it contains pointers to segments at all available quality levels, and the player chooses which to download based on current network speed. Manifest files are small text files but are security-critical: streaming services generate signed, short-lived manifests tied to the user's streaming token to prevent sharing or tampering.